Incremental Valicuty: An applied study using different informants and measurements

The incremental validity study is an important psychological assessment topic that has been not study very much from psychometrics. In this study, we analyse the children incremental validity reported by different informants (children, classmates, and teachers). The sample comprised 525 schoolchildren (41.3 % boys) in a longitudinal study, ranging at age from 9 to 14 years (12.72 mean; SD =1.57) across the three consecutives years of measurement. In order to predict the maternal behaviour, self-reported source shows the higher incremental validity over hetero-reported source. We discuss alternative methods to study the incremental validity.